Super sewer campaigners in Fulham have been left stunned after Thames Water today announced Carnwath Road as its preferred site from which to build part of the massive tunnel.

The utility firm faced a straight choice between heavily populated Carnwath Road and a green space in Barn Elm, Putney. And, after months of protests from both sides of the river, has plumped for Fulham as its preferred choice.

Protest group RATS is amazed by the decision and believes Thames Water has been influenced by political heavyweights like Richmond MP Zac Goldsmith as well as what it believes has been a propaganda campaign from rival Putney campaign group StoptheShaft.

Ann Rosenberg Bell, spokeswoman for RATS, said: "This decision stinks of political interference. We are outraged Thames Water appear to have come to a cynical, politically-motivated decision which puts trees before people.

"Our own detailed site appraisal submission to the company shows beyond doubt that the commercial and human cost of choosing Carnwath Road rather than Barn Elms would be needlessly far more expensive.

"So it’s a bad deal for Thames Water customers, who are going to have to foot the entire inflated bill for this questionable and hugely disruptive scheme, and a terrible injustice for the community of South Fulham. Thames Water know it, and they know we know it."

Arch critic, council leader Stephen Greenhalgh, called the decision 'ludicrous', saying: "Blighting the lives of thousands of Fulham residents, threatening homes, jobs and local schools - not to mention the disruption on our roads - for six years is outrageous.

"We will continue to defend residents' and water bill payers' interests by highlighting the sensible alternatives to cleaning up the Thames that do exist."

Thames Water insists its decision was not politically influenced but based on engineering logic. It believes it can use larger barges to transfer soil from the digging because of the site's downstream position and that using Fulham would prevent the need to divert a section of Thames Path. It would also 'prevent the temporary loss of sports pitches' in Barn Elms.

RATS believes the disruption to residents in Fulham from the project, which could last up to six years and involve periods of 24-hour digging, has the potential to make lives a misery and is preparing to fight Thames Water's decision all the way.

Ms Rosenberg added: "Up to now we have endeavoured to engage with Thames Water in a constructive, co-operative spirit. We will maintain a dialogue with Thames Water but will now have to use all other protest options open to us to persuade them to revert to their original choice of Barn Elms."

A 14-week consultation period now begins and MP Greg Hands believes all is not lost. He said: "This is not a final decision and I will continue to fight for an alternative to be found. We have lost this significant battle, but the war is not over on this."

Thames Water's Phil Stride said: "There are no easy choices when it comes to selecting construction sites, but our focus during this latest phase of consultation will be to work with communities around our revised list of preferred sites to ensure we understand and address their concerns effectively.

"It is particularly important that we listen to local people’s views on what individual sites should look and feel like after construction work has finished."